The initial and probably the main reason for the PHP 5.1.1 release in such a hurry was a rather interesting problem. One of the features introduced by 5.1.0 was the addition of the native "date" class. The eventual plan was to enable additional ext/date functionality via this class through a series of methods that have already been written.

The real "fun" began a couple of hours after the release when Pierre-Alain Joye posted a message titled "PHP 5.1 (Or How to break tousands of apps out there)", whose title was certain to provoke a reaction and boy, did it ever.

He continues, talking more about the dissention that it caused on the internals mailing list. He does mention, however, that the bugs.php.net site was interestingly quiet the whole time. With Ilia being the "Release Master" for the 5.1 series, he decided eventually to pull it back and wait until a future date to make the date class release...